Flat face tape scale indicator

ABSTRACT

An indicator tape is supported by idler pulleys in a flat position in front of a flat viewing window and is attached to a rotatable drum actuated by an amplifying linkage connected to a condition responsive means such as a Bourdon tube or diaphragm means for sensing a condition. The tape may be either endless or may have its other end attached to a spring-loaded return drum. The linkage connection between the bellows and the drum includes a zero adjustment and a range adjustment. A light transmitting plastic block is positioned behind the tape at the viewing window and is provided with cavities in which are mounted lights to illuminate the block and tape.

llnited States Patent Raznov et al.

[15] 3,656,451 [451 Apr. 18, 1972 [54] FLAT FACE TAPE SCALE INDICATOR[72] Inventors: Jerry L. Raznov, Philadelphia; Donald E.

Warren, Quakertown, both of Pa.

[73] Assignee: Ametek, Inc., New York, NY. [22] Filed: May 15,1970

[21] Appl. No.: 37,522

[52] U.S.Cl ..1l6/70, 73/410, 116/135 [51] 1nt.Cl. ..G0ll 19/12 [58]Field ofSearch ..ll6/65,70,135, 114,129; 74/89; 73/178, 407, 410, 344,386; 340/27, 316; 40/130 [56] References Cited UNITED STATES PATENTS I3,033,155 5/1962 Beckman ..1l6/l29 3,117,312 1/1964 Watson ..340/3163,241,256 '3/1966 Viret et a1 ..40/130 2,185,971 1/1940 Achtel et a1....73/410 2,284,588 5/1942 Rineer 73/410 2,477,233 7/1949 Bristol......73/410 2,627,750 2/1953 Titus 73/410 X 2,656,721 10/1953 Melchior..73/389 2,744,489 5/1956 Gallant ..1 16/ 129 2,804,041 8/1957 Neugass....1 163/129 3,126,744 3/1964 Hermanns ..73/407 3,139,854 7/1964 Hedgeset al. ....1 16/135 3,158,029 11/1964 Fischer ..73/407 3,354,722 ll/1967Waite et al... ..73/407 3,439,648 4/1969 Miller et al.. ....1 16/1353,512,499 5/1970 Runde et al ..l l6/l29 Primary ExaminerLouis .l. CapoziA!t0rneySmythe & Moore [5 7] ABSTRACT justment. A lighttransmittingplastic block is positioned behind the tape at the viewingwindow and is provided with cavities in which are mounted lights toilluminate the block and tape.

1 Claims, 9 Drawing Figures PATENTEBAPR 18 1912 3,656,451

' sum 2 [IF 2 INVENTORS JERRY L RflZ/VOV Damqzo WA REN ATTORNEYS FLATFACE TAPE SCALE INDICATOR In modern instrumentation, particularly inaircraft, the greatest problem is to provide engine and otherinformation with maximum readability and the highest reliabilityconsistent with simplicity and economy. The instruments indicating thesedifferent functions must be simple in construction so that maintenanceis no problem, and these instruments must be packaged in relativelysmall cases so as, to occupy a minimum of space. In view of theincreasing number of instruments on aircraft instrument panels, it hasalso become desirable to reduce the frontal face area of theseinstruments. As the size of the instrument is decreased, it becomes moredifficult to see the indication from a distance or even to obtain aquick approximation of the value indicated. Another consideration isthat the light reflecting on the viewing window must be held to aminimum, or even eliminated, so that the instrument can be easily readfrom different angles and under various conditions.

One of the objects of the present invention is to provide an improvedvertical scale indicator instrument.

Another of the objects of the invention is to provide an improvedlighting arrangement for the viewing window of a vertical scaleindicator instrument.

It is another of the objects of the invention to provide a verticalscale indicator instrument having simple and accurate zero and rangeadjustments.

According to one aspect of the present invention, a linear or flat-facedscale indicator instrument may include a rotatable drum having indicatortape means attached to the drum for movement therewith. Means which mayinclude spaced idler pulleys are employed for positioning a portion ofthe tape means in a vertical position adjacent to a flat viewing window.A scale having transparent or translucent portions is mounted on theviewing window so as to be superposed over the fiat portion of the tapemeans. The scale also could be on the tape with suitable reference marksassociated with the viewing window. Condition sensing or conditionresponsive means, which may be bellows means, diaphragm means or Bourdontube means, are operatively connected by linkage means to the rotatabledrum so that the drum moves the tape means in response to a sensedcondition. Means are mounted behind the tape means for lighting the tapemeans and scale to facilitate viewing thereof through through the flatviewing window. The tape means may be continuous and pass over therotatable drum or may be of a definite length with one end beingattached to the rotatable drum and the other end attached to aspring-loaded return drum. The tape normally would be used in a verticalposition, but it is to be understood that the viewing or indicatingportion may be other than vertical and that the term vertical as usedherein includes such.

Other objects, advantages, and features of the present invention willbecome apparent from the accompanying description and drawings, whichare merely exemplary.

In the drawings:

FIG. 1 is a front elevational view of the indicator instrument accordingto the present invention showing the viewing window, scale, and flattape portion;

FIG. 2 is a side elevational view of the instrument with a portion ofthe sidewall being cut away;

FIG. 3 is an overall perspective view of the indicator tape used in theinstrument of FIG. 1 and 2;

FIG. 4 is a side elevational view in enlarged scale of the drum movementand bellows with the center fitting being shown in section;

FIG. 5 is an end elevational view of the bellows assembly shown in FIG.4;

Proceeding next to the drawings wherein like reference symbols indicatethe same parts throughout the various views, a specific embodiment andmodifications of the present invention will be described in detail.

As may be seen in FIGS. 1 and 2, an instrument according to the presentinvention is indicated generally at 10 comprises a case 11 having acover 12, only a portion of which is shown in position in FIG. 2. Withinthe casing is mounted a rotatable drum 13 around which is positioned acontinuous endless indicator tape 14 secured in position to drum 13 bymeans of a positive tape drive pin 15. Tape 14 is shown in greaterdetail in FIG. 3 and includes a translucent portion 16 and an opaque orcontrasting portion 17. The boundary 18 between the translucent andopaque portions forms an indicator mark or line which is readily visibleas can be seen in FIG. 1.

The tape 14 passes over a pair of idler pulleys l9 and 20 which supportthe tape in the form shown in a vertical position as indicated at 21before a flat viewing window 22 having a viewing glass 23 therein. Asuitable scale 24, which is in the form of a vertical dial, may bepositioned next to a narrow vertical slot 25 through which can be seenthe tape 14. FIG. 8 shows the scale on the tape and a reference on thewindow.

The tape 14 passes over a tensioning pulley 26.

The two idler pulleys l9 and 20 may be of a transparent plastic or othersuitable material. Light block 27 may be formed of the same material orlight transmitting material positioned behind the fiat portion of thetape as shown in FIG. 2. The block can be transparent or translucent.The light block is provided with two or more cavities 28 in which arepositioned lamps connected to a suitable source of electrical energy sothat energization of the lamps enables light to be transmittedthroughout the entire plastic block to facilitate viewing of the tapeand scale. The light block can be toned for controlled brightness anduniformity.

In the embodiment of the invention illustrated in FIG. 2, the conditionresponsive means comprises a pair of bellows 30 and 31 whose outer endsare fixedly attached at 32 within the casing and whose inner ends areattached to a center fitting 33 which is movable. The fitting 33 has aneccentric bushing 34, screw 35 being threaded within the bushing.One'end of screw 35 is provided with a slot 36 to permit adjustmentthereof by means of a tool and the other end is provided with a ball 37which is received in a U-shaped channel section 38 formed on the tail ofa sector gear 39. Sector gear 39 is pivoted at 40 and meshes with apinion 41 which comprises part of the amplifying movement indicated at42. With this arrangement, the relatively small linear motion of thecenter fitting 33 is amplified approximately 30 times by means of thislinkage and gear arrangement to the rotatable drum. The amplificationwill be dependent upon the parts and their dimensions.

Coarse zero adjustment may be accomplished by setting the drum 13 withrespect to the pinion 41. Fine zero adjustment may be accomplished byrotation of the eccentric bushing 34 which can be arranged to compensatefor approximately 20 percent of the total scale. A look screw 43 may beprovided for setting the eccentric bushing in its adjusted position.

The degree of amplification and the range may be adjusted by rotation ofscrew 35 which will vary the distance between the ball and slideconnection 37 and 38 from the sector pivot 40. Screw 35 is set in itsadjusted position by means of lock nut The instrument shown in FIG. 6 isindicated generally at 50 and employs an open loop indicator tape 51.One end of tape 51 is attached to drive drum 13, and the other end isattached to a spring-loaded constant tension take-up drum 52.Structurally, the remaining elements of the modified instrument 50 I aresimilar to those of the instrument 10.

FIG. We claim a view similar to that of FIG. 2 but showing amodification employing an open indicator tape;

FIG. 7 is a view similar to that of FIG. 6 and showing a furthermodification of an instrument employing an open tap'e; FIG. 8 is afragmentary view of an alternate arrangement of the scale; and

FIG. 9 is a schematic view of another form of the invention.

In FIG. 7, there is shown another instrument having an open loop butwithout use of a light block. In a similar manner, tape 53 has one endattached to a drive drum l3 and the other end attached to aspring-loaded take-up drum 54.

While the sensing means have been disclosed as comprising of bellows, itis pointed out that diaphragms or Bourdon tubes could also be used.

In the bellows assembly as illustrated in the drawings, both bellows aregeometrically and physically identical so that any change in ambientpressure will be balanced on each opposing bellows and will not affectmotion resulting from the internal pressure differential. The sensingelement can be utilized to monitor either absolute, gauge, ordifferential pressure. To indicate absolute pressure, one side of thebellows assembly is highly evacuated and sealed while the oppositebellows remains as the sensing element. For the indication of gaugepressure, one bellows will be open to atmospheric pressure and the otherbellows senses vacuum or pressure. To monitor differential pressure,each bellows senses a specific pressure and mechanically sums same.

In place of the two bellows, such as seen in FIG. 2, a single bellows orcondition responsive means 60, FIG. 9, can be employed, the bellowsbeing connected at one end to fitting 61 which is similar to fitting 33,FIG. 2, with the related adjustment parts. Shaft 62 extrudes fromfitting 61 and is guided in bearing means 63.

The assembly seen in FIG. 9 is placed in an enclosure 64 which can bemade pressure tight.

The arrangement seen in FIG. 9 can be used in various manners. Forexample, if used as an absolute pressure monitor, the bellows 60 can beevacuated and the vacuum or low pressure to be sensed connected to theinterior of the case.

If the arrangement is to be employed as a gauge pressure monitor, thenthe ambient pressure is connected to the case and the pressure to bemonitored connected by line 65 to the interior of the bellows. If thedevice of FIG. 9 is to be used to monitor a differential pressure, thenone pressure is connected to the interior of the case and the secondpressure connected to the interior of the bellows Thus, it can be seenthat the present invention has disclosed a linear scale indicatorinstrument employing a unique and simple mechanical amplifier and apressure sensing element. The instruments can be generally considered asbeing in the medium-low to high-pressure range and can be used tomonitor absolute, gauge, or differential pressures. Such pressures couldinclude engine manifold pressure, fuel flow, cabin altitude pressure,oil pressure, and the like.

It will be understood that various details of construction andarrangement of parts may be made without departing from the spirit ofthe invention except as defined in the appended claims.

We claim:

1. In a flat-faced scale indicator instrument, the combination of arotatable drum, indicator tape means connected to said drum for movementtherewith, transparent idler pulley means for positioning a portion ofsaid tape means adjacent to a relatively flat viewing window, scalemeans in said window adjacent to the flat portion of the tape means,condition sensing means, linkage means operatively connecting saidsensing means in said rotatable drum so that the drum moves the tapemeans in response to the sensed condition, and lighting means comprisinga block of light transmitting plastic material positioned between saidpulley means and behind the flat portion of said tape means, havingrecess means therein, illumination means within said recess means sothat energization of the illumination means will illuminate the plasticblock for lighting the tape means and scale to facilitate viewingthereof through the fiat viewing window.

1. In a flat-faced scale indicator instrument, the combination of arotatable drum, indicator tape means connected to said drum for movementtherewith, transparent idler pulley means for positioning a portion ofsaid tape means adjacent to a relatively flat viewing window, scalemeans in said window adjacent to the flat portion of the tape means,condition sensing means, linkage means operatively connecting saidsensing means in said rotatable drum so that the drum moves the tapemeans in response to the sensed condition, and lighting means comprisinga block of light transmitting plastic material positioned between saidpulley means and behind the flat portion of said tape means, havingrecess means therein, illumination means within said recess means sothat energization of the illumination means will illuminate the plasticblock for lighting the tape means and scale to facilitate viewingthereof through the flat viewing window.